Hi,
So after getting a positive answer abouth whether a S6-53DZ will fit with a KLRacing adapter, I hit another wall-the flywheel, clutch, pressure plate "assembly".
Will the splines of the gearbox input shaft match a whiteblock's clutch's?

If not- what should I do? I don't think a BMW clutch would fit- the flywheel and pressure plate are different.
And I have read that the flywheel holds the crank position sensor, so that can't be changed.

People have done this before, but nobody says anything about the flywheel and clutch.
Anybody here have an answer?
One more thing- the bmw gearbox's input shaft is said to be too short, so would a flywheel spacer fix that?

You'll have to (naturally)use a disc with BMW spline. Options are stock BMW 240mm disc or sintered aftermarket with unsprung center. There may be a sintered disc with sprung center available now. It'll give more life to the splines on input shaft and disc and dampens the rattling noises. Any BMW disc won't do, it has to be for GS6-53.

Sintered disc thickness can be chosen close to stock Volvo so you don't have to shim pressure plate position outwards from flywheel at all or max ~0.5mm. BMW disc is ~9.5mm thick so it should be machined around 2mm deeper into the flywheel.

What sort of application are you using, hp/torque? Just thinking if you'll need a stiffer pressure plate in which case visit to a machine shop is ahead any way. Stock flywheel can be machined for your needs.

I think you'll need a flywheel spacer with a transmission adapter plate. I have no experience because both of my transmissions have been modified for Volvo bellhousing.

If the gearbox input shaft is too short then it is best to either use a wider spigot bearing in the flywheel (if it is just too short) or machine a spacer that presses into the flywheel and holds the spigot bearing in the right place (if you need more length).

As for the clutch, any decent clutch shop should be able to take a clutch plate with the Volvo splines and replace it with the BMW spline. You may even find that a clutch plate is available off the shelf with the right diameter and splines, again a good clutch shop should be able to look that up for you.

What sort of application are you using, hp/torque? Just thinking if you'll need a stiffer pressure plate in which case visit to a machine shop is ahead any way. Stock flywheel can be machined for your needs.

4-cylinder whiteblock, probably T4 1.9.
Reason is that the swap will be in a non-Volvo chassis and the engine bay is quite small.

Find a local clutch shop to build you a custom clutch. Give them your pressure plate & flywheel, and tell them what trans is going in. They'll make a custom disc and set the stack height where it needs to be, etc.

You can buy separate parts from KL racing - clutch hubs, sprung and unsprung plates. Maybe you can even get the right BMW clutch plate there, Volvo pressure plate and have flywheel friction area turned down 2mm per Lankku's info.